Sewing machine



s. J. HAMLETT 2,886,390

May 12, 1959 SEWING MAcHINx/a Filed oct. 25, 1956 2 sheets-sheet 1 ,3 ff f /4 May 12, 1959 sra. HAMLETT 2,886,390

SEWING MACHINE: l med oct. 2s, 195s z sheets-sheet 2 Fica. 3

uw SN M BY wl Afro Y ve-X5 United States Patent-" SEWING MACHINE Sidney J. Hamlett, Parma, Ohio, assignor to White Sewing Machine Corporation, Lakewood, Ohio, a corporation of Delaware j 4 Application october 2s, 1956, serial N6. 617,709

6 claims. (cl. sip-so) This invention relates to sewing machines and, more particularly, to a booster device to-assist the operator in raising 'the machine head from within the storagewell of its supporting cabinet to its operative position externally thereof, and to prevent said machine head from suddenly dropping into the storage well when it is being returned thereto.

The principal object of the present invention is to provide a novel and simplied booster device for a As'wingable sewing machine head that is continually operative throughout the operative cycle of raising and lower? Fig. 1 is a fragmentary sectional view through a sewing machine cabinet, there being shown in side elevation one embodiment of a booster of the present invention and the associatedsewing machine head in its lowered or storage position within the cabinet;

Fig. 2 is a fragmentary view similar to Fig. 1 but with` the booster and sewing machine head shown in the relationship they have when the head is in its mostA raised position;

Fig. 3 is a fragmentary view similar to Figs. 1 and 2 with the booster and head in the relationship they have duringfnormal use of the machine;

Fig. 4 is a front elevational view of the booster of Fig. 1 in its extended or uppermost position with the' sewing machine head detached from the cabinet;

Fig. 51 isa fragmentary side elevational View of the booster of Fig. 1 showing the parts thereof held in still another position from those previously illustrated and oneI` adapted for shipment of the cabinet without the sewing machine head attached thereto; and

second embodimentof boosterdevice of the present invention, aportion of the cabinet being shown in section f.

while a portion of the sewingmachine head is shown in elevation. y

xGenerally, the presenti` invention comprises4 a spring operative booster that exerts an upward force upon .tl:1e65

sewing machine head to assist the operator in raising or lowering the head out of or into its storage well within the cabinet and to prevent unrestrained down-y ward movement of the head.

More specifically, and with reference tothe drawings f wherein' like elementsl are designated by. like. reference 6 is afragmentary side elevational View of a Patented May 12, 1959-- ice chine cabinet of known construction and having a work -l supporting table or top 3.

- pivotal connection is provided with the usual flap 12,r

characters, the 'numeral 2, Fig., l, -denotes a sewingma-V i An opening 4 formed within the top 3 permits the sewing machine head 6 to be raised therethrough out of its storage well 7 within the cabinet and into its operative position as shown in Fig. 3.

The rear longitudinal edge of base or bedplate 9vof machine head 6 is pivotally attached to the cabinet atl the rear longitudinal side of the opening 4 by any suit-v able means such as pins 11 as will be well understood. The longitudinal side of opening 4 opposite to said Fig. 3, which is arranged to swing about pin 13 upwardly out of said opening to permit passage of the base. plate 9 and supported machine head 6 therethrough. 'I

Plate 10, attached to the underside of upper wall 3 and extending horizontally into storage well 7, is arf ranged to provide support for said ap 12 when it is-` placed in the position as shown in Fig. 3.

The free end of ap 12 is provided with a shelf 14 which is arranged to support the free end of baseplate 9 of machine` head 6.

A booster, denoted generally by the numeral 16, Figs.

3 and 4, comprises a substantially rectangular base platel 17, and a downwardly extending U-shaped bracket 18y formed integrally on one end thereof having spaced and. opp'osed wall members 19 and 21, interconnected by back plate 22, extending transversely therebetween and de-r iining spring chamber 23. An extension 24 of wall member 19 lies against and is secured to the underside of base plate 17 to provide additional rigidity thereto.

Suitable apertures 25, formed in base plate 17 and extension 24 provide for the attachment of the booster to and within the cabinet by means of screws 26 extendl ing therethrough and into a structural element of the cabinet.

A coil spring 31 is disposed Within spring chamber 23v and surrounds a cylindrical spacer bushing 28 fastened between walls 19 and 21 of bracket 18 by means of shaft 29. i

One end of coil spring 31 is provided with an outixwardly extending finger 32, Fig. 3, which is arranged to be in pressure engagement with the bottom edge 33 of end plate 22, and the opposite end of said spring is formed into a hook 34, Fig. 4, which is arranged to embrace a flanged stub shaft 35 disposed on the end of' arm 37 of .toggle lever 38 to be presently described.

Toggle lever 38 comprises a substantially ilat circular portion 39 rotatably mounted upon shaft 29, and disposed within spring chamber 23, between the bushing 28 and wall member-19 of bracket 18. Arm 37 is integrally formed with said circular portion 39 and extends radially outward therefrom and is substantially coplanar therewith.

Booster lever 42, generally L-shaped in configuration, is pivotally mounted on the outer side of wall 19 of bracket member 18 by means of headed stub shaft 43 and is displaced radially and upwardly relative to shaft 29.

A roller 57 is rotatably displaced on the free end 58 of lever 42 by means of pin 59, being positioned thereon so that the peripheral surface of said roller;

extends above the extremity of said free end 58, and is;v

arranged -to lengage the underside of base 9 of machine.,

head v6..

A stop lug 61 may be formed'on lever 42 adjacent its4 pivot to vengage the underside of leg 24 and limit up-- ward movement of said lever.

:i A spacer plate 45 having a substantially U-shaped sloti.;- 47, is interposed between wall 19 and lever 42, wherein;

the headed-end 46'of bearing shaft 29 is partiallyfdisyposed .within `slot.47 and enables said lever 42 to rotate.:l

freely without interference from any protruding elementsdisposed on bracket 18.

A toggle link 51 at one end is pivotally connected to the. free end of arm 37 of toggle lever 38 by means of stub shaft 35 and at its opposite end is pivotally connected to lever 42 substantially midway of its ends by means of headed pin 53. The interconnection between levers 38 and 42 provides a oatable toggle connection whereby any force that is applied to either may be transmitted to the other lever, and a variable mechanical advantage will be realized thereby when raising and/or lowering the machine head 6.

Lever 42 and link 51 may also be olfset at 54 and 5S respectively, to enable them to be interconnected while utilizing only a minimum of space.

Coil spring 31, having the finger 32 on one end in pressure engagement with the lower edge 33 of end plate 22 of bracket 18, and the hook 34 on its opposite end embracing stub shaft 35, tends to bias lever 38 counterclockwise as shown in Figs. 1-3. The force exerted by sa-id spring is transmitted to the lever 42 by means of connecting link 51 wherein said lever 42 is also biased in a counterclockwise direction, and the roller 57 on the end thereof is brought into positive pressure engagement with the underside surface of the base plate 9.

. In operation, when the sewing machine is not being Used, the head 6 thereof is usually lowered into the storage well 7, and retained in the position as depicted in Fig. 1.

Preparatory to lowering the machine head 6 to within the cabinet, it is grasped and raised slightly to a position whereby the ap 12 may be swung upwardly out of the opening 4. The head is then lowered and allowed to pivot about pin 11 downwardly toward and into the storage well 7.

The resultant force produced by the mass of the machine head 6 is transmitted to the booster lever 42 by means of the interengaged base plate and roller 57. The lever 42 is rotated clockwise as viewed in Figs. 1-3 about its stub shaft 43 against the bias of coil spring 31.

As the lever 42 is lowered into the storage well 7, toggle lever 33, being connected thereto through toggle link 51, is also rotated clockwise about its supporting shaft 29. The hook 34 of spring 31, being connected to arm 37 of said lever 38, is movable therewith, resulting in further ceiling said spring and thereby increasing its biasing eiect.

Thus, with the above delned structure, it is realized that the spring bias is a minimum when the head 6 is raised to the position shown in Fig. 2 and is progressively increased as it is lowered into -the storage well 7 to the position depicted in Fig. l.

Additionally, as the head 6 is lowered into storage Well 7, the elect of the mass of said head upon lever 42 increases as the head is moved from a position as shown in Fig. 2 'to a position as shown in Fig. 3 where at said latter position it exerts its maximum rotating elect upon lever 42. And, as the head 6 is further lowered into said storage well 7, from its Fig. 3 position to its Fig. l position, the rotating effect of machine head 6 upon lever 42 is decreased.

Therefore, during the cycle when the machine head 6 is lowered into the storage well 7, the bias of spring 31 steadily increases while at the same time, the effect of the mass of machine head 6 to rotate the lever 42 increases to a maximum and then steadily decreases.

When the machine head 6 has been lowered to a position as shown in Fig. 1, the bias of spring 31 acting upon lever 42 through link 51 and the rotating eiect or force of machine head 6, are equal in magnitude and opposite inv direction whereby the machine head 6 attains its rest position within storage well 7.

It is readily ascertainable that by. selecting the size of spring, and placement of link connection any desired reaction may be obtained therefrom which may change the 3 of cabinet 2, the flap 12 is raised upwardly out of opening 4, and the machine head 6 is then grasped and rotated upwardly out of storage well 7. Y

The spring 31, exerting its maximum force upon booster lever 42 through the interconnecting toggle link 51, provides an upwardly directed force upon machine head 6,

l whereby a minimum of effort is required of the operator in raising said machine head to its operative position.

As the lever 42 is forced upward, the bias of spring 31 decreases, but is more advantageously applied to lever 42, through the link 5.1. and arm 37 of toggle lever 38 interconnected by stub shaft 35 providing a lloatable fulcrum, since the point of application of the spring bias upon link 51 moves away from the shaft 43, about which lever 42 pivots.

As the machine head 6 is raised upward, the roller 57 rotates over the underside of base plate 9, enabling the effort of spring 31 to be continuously applied to said machine head.

The lever 42 is rotated counterclockwise until lug 61,

Fig. 2, on said lever engages the underside of extension 24 of wall member 19.

shown in Fig. 3, preparatory to lowering the machine' head 6 to its operative position.

It may be desirable to utilize the same booster device' on various sewing machines wherein the weight of the' machine head is substantially different. For instance, on a machine wherein weight is an important factor and a lightweight machine head is utilized, the force exerted by the booster device may be in excess to that required and is alone suicient to raise the machine head out of the cabinet to a position above the usual operating position. To prevent this from occurring, a link or lock member 63, Figs. 4 and 5, is provided and is formed with a cut-out portion 64 on its free end defining a shoulder 65, and which is arranged to be pivotally fastened to lever 42 adjacent shaft 43 by means of screw 66. By moving and securing said lock member into a position wherein the cut-out portion 64 thereof is arranged to receive the edge of extension 24 of well member 19 on the upward swing of the machine head and the shoulder 65 abuts against the side of said extension 24 in the manner shown in Fig. 5, further counterclockwise or upward movement of lever 42 is restricted once the machine head has been raised to its operating position.

Also, to make certain that the booster lever 42 moves upward with the machine head 6, means are provided such as plate 68 depending from the underside of bedplate 9 and having a pin 68a extending substantially perpendicularly outwardly therefrom and positioned to engage lever 42. As the machine head 6 is raised upwardly out of storage well 7, the pin 68a strikes the lever 42 whereby said lever follows the upward movement of thel head 6.

In Fig. 6, a modified embodiment of booster is 'dis'- closed wherein the bushing 28 and toggle lever 38 arel replaced by a bearing 71 rotatably supported upon shaft 29 within bracket 18, and being formed with a groove 72 on one end thereof and extending diametrically there- A lug 7S, formed integrally with toggle lever 73 and'V extending normally thereto, is provided with a slot into; which the hook end 34 of coil spring 31 is seated.

When the machine head is raised out of the storage well, the spring 31 exerting its force upon booster lever 42 through the interconecting toggle lever 73 and toggle link 51, provides an upwardly directed force upon the base plate 9 of the machine head. Upon lever 42 rotating upwardly, the toggle lever 73 is also pivoted and rotates bearing 71 counterclockwise about its supporting shaft 29.

When the machine head is lowered into the storage well 7, booster lever 42 is rotated clockwise forcing toggle link 51 downward to pivot the toggleV lever 73 and bearing 71 clockwise whereby the spring 31 is re-coiled.

Therefore, it is noted that the direction of rotation of the bearing 71 and toggle lever 73 is the same as that of spring 31 as it coils and/ 0r uncoils depending upon the movement given the machine head, whereby the frictional forces therebetween are reduced to a minimum.

Having thus described several embodiments of the present invention it will be realized that the aforesaid objects and advantages have been attained, and that the inventive concepts herein are susceptible of various modications without departing from the scope of the claims herein.

Having thus described my invention, l claim:

1. A booster device for a sewing machine of the drop head type having a cabinet defining a storage well comprising, a U-shaped support adapted to be secured within the well and having a spring chamber in said U-shaped support, a booster lever pivoted at one end to one leg of said U-shaped support and the opposite end arranged to movably engage the underside of the head, a variable force applying toggle interconnecting said booster lever and U-shaped support including a toggle lever having one end pivotally mounted in said spring chamber and on an axis spaced radially to said booster lever pivotal connection and its opposite end pivotally connected to one end of a toggle link, the opposite end of said toggle link being connected to said booster lever substantially mid-way its ends, a coil spring located in said spring chamber and movable about the pivotal axis of said toggle lever and having one end anchored to said U-shaped support and the opposite end connected to the toggle lever and toggle link at the pivotal connection therebetween.

2. The booster device as defined in claim 1 and wherein the toggle link is movable relative to said toggle lever and operative to apply a variable force from said spring means to said booster lever.

3. The booster device as defined in claim 2, and wherein the toggle link is movable relative to the toggle lever and booster lever.

4. A booster device for a sewing machine of the drop head type having a cabinet ldefining a storage well comprising, a support adapted to be secured within the well and having only one spring chamber, a booster lever pivoted at one end to said support and the opposite end having roller means in constant engagement with said head, a variable force applying toggle interconnecting said booster lever and support including a shaft secured in said spring chamber on an axis spaced radially to said booster lever pivotal connection, a toggle lever having one end pivotally mounted upon said shaft and its opposite end pivotally connected to one end of a toggle link, the opposite end of said toggle link being connected to said booster lever at a point substantially mid-Way its ends, a bushing surrounding said shaft, a coil spring mounted over said bushing and movable within said spring chamber and having one end anchored to said support and the opposite end connected to the toggle lever and toggle link at the pivotal connection therebetween.

5. A booster device for a sewing machine of the drop head type having a cabinet dening a storage well comprising, a support adapted to be secured within the well and having a spring chamber, a booster lever pivoted at one end to said support and the opposite end having roller means in constant engagement with said head, a variable force applying toggle interconnecting said booster lever and support including a shaft secured in said spring chamber on an axis spaced radially to said booster lever pivotal connection, a lever pivotally connected to said booster lever and arranged to be moved for engagement with said support to stop the movement of said booster lever in a plane intermediate its upper and lower limits of movement, a toggle lever having one end pivotally mounted upon said shaft and its opposite end pivotally connected to one end of a toggle link, the opposite end of said toggle link being connected to said booster lever at a point substantially midway its ends, a bushing surrounding said shaft, a coil spring mounted over said bushing and movable Within said spring charnber and having one end anchored to said support and the opposite end connected to the toggle lever and toggle link at the pivotal connection therebetween.

6. A booster device for a sewing machine of the drop type having a cabinet defining a storage Well comprising, a support adapted to be secured within the well and having only one spring chamber, a booster lever pivoted at one end to said support and the opposite end arranged to movably engage the underside of said head, a variable force applying toggle interconnecting said booster lever and support and including a shaft mounted within said spring chamber at an axis spaced radially to said booster lever pivotal connection, bearing means rotatably supported upon said shaft and having groove means formed therein, a toggle lever having one end pivotally mounted upon said shaft and disposed in said groove means and the opposite end pivotally connected to one end of a toggle link, the opposite end of said toggle link being connected to said booster lever substantially mid-way its ends, a coil spring mounted upon said bearing and having one end anchored to said support and the opposite end connected to the toggle lever and toggle link at the pivotal connection therebetween, and said coil spring being mounted upon said bearing such that said bearing and toggle lever are rotatable in the same direction as said spring coils and/ or uncoils while said head is being moved to its several positions.

References Cited in the file of this patent UNITED STATES PATENTS 933,070 Gleason Sept. 7, 1909 1,639,094 Klein Aug. 16, 1927 1,756,638 Etore Apr. 29, 1930 1,801,840 Baneld Apr. 21, 1931 2,318,443 West May 4, 1943 2,711,940 Hochman June 28, 1955 2,789,875 Van Ordt Apr. 23, 1957 2,790,690 James Apr. 30, 1957 

